In wireless networks, stations disposed along the propagation path of a transmission may overhear the broadcast information even though the packet may not be addressed to the overhearing station. Such a situation may also occur, for example, in spatial multiplexing systems in which transmissions may occur simultaneously among multiple stations in the same time slot and at the same frequency. Such multiple transmissions may, however, result in interference with intended transmissions by transmissions that are not intended for a given stations. Furthermore, utilization of relay transmissions is capable of increasing both the capacity and reliability of a wireless network. In a wireless network using relays, in the downlink the base station sends a packet to the relay station, and the relay station then forwards the packet to the destination station in a later time slot. When the relay station retransmits the packet, the retransmitted packet can create interference to the base station and prevents the base station from reliably receiving normal uplink data from another station in the same frequency and time location.
It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.